Nope. It's the listing agent Realtor's job, (or their transaction coordinator, or their short sale negotiator,) to follow up with the seller's mortgage holder but really, no amount of hounding makes a difference in my experience. Buyers do not have any direct access to the people making the decision for the seller's side. You'll have to be patient.
Of course, you can keep looking in the mean time and something better could come along. Bank's loss, your gain. Until you have confirmed acceptance of their acceptance of your offer, you are free to move on to another property if you so choose.